In this paper, a probability model leading to a Yule distribution is developed in the study of surname frequency data. This distribution, suitably truncated, is fitted to actual data as an alternative to the discrete Pareto distribution, with quite satisfactory results

The problem of determining how family names evolve preoccupies both statistics and human biology. The determination of a proper and well justified probability model to describe the probability distribution of surnames has been confronted by many authors. In this paper two stochastic models...

The EWMA control chart is used to detect small shifts in a process. It has been shown that, for certain values of the smoothing parameter, the EWMA chart for the mean is robust to non normality. In this article, we examine the case of non normality in the EWMA charts for the dispersion. It is...

A stock replenishing model is considered whereby not only the demand for the item, but also the stock in hand and the lead time period are considered to be random variables. The interrelations of these three item characteristics are then studied in the framework of a scheme for deciding when to...

Measurement error is a usually met distortion factor in real-world applications that influences the outcome of a process. In this paper, we examine the effect of measurement error on the ability of the EWMA control chart to detect out-of-control situations. The model used is the one involving...